During a recent study, it was discovered that monkeys will punish others who get more than their fair share.

Researchers believe the spiteful trait humans posses may go back much farther into our evolutionary history than previously thought.

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During a recent study, monkeys punished others they felt had more than their fair share. Researchers now believe the spiteful trait humans posses extends much deeper into our evolutionary history than previously thought

'One hallmark of the human species is the fact that we're willing to make a special effort to punish those who violate social norms' said Laurie Santos, Yale psychologist and senior author of the study.

'We punish those who take resources unfairly and those who intend to do mean things to others.'

'Many researchers have wondered whether this motivation is unique to our species.'

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Researchers found Capuchin monkeys will yank on a rope to collapse a table that is holding another's food.

CHIMPANZEES CAN TELL RIGHT FROM WRONG

A study of the apes reacting to an infant chimp being killed by another group has shown the animals have a strong sense of right and wrong.

The researchers found chimpanzees reacted to videos showing the violent scenes in a similar way to humans.

The researchers, whose study is published in the journal Human Nature, filmed 17 adult chimpanzees from two different zoos in Switzerland as they watched video clips.

The findings suggest that chimpanzees can distinguish between aggression against infants compared to other violent forms of behaviour.

However, the researchers also found while the chimps watched the infanticide scenes for longer, there was only limited evidence they became agitated or reacted to them.

While chimpanzees will only do so if they feel a crime has been committed by another monkey, such as stealing the food.

The study showed that Capuchins punish their fellow kind much more, even in the occasion the other monkey just had more food.

Santos and her colleagues Kristin Leimgruber and Alexandra Rosati, now both at Harvard University, wanted to know if a distantly related primate species would punish the beneficiaries of social inequalities.

Like chimpanzees, Capuchins did collapse tables to punish monkeys that stole food.

But they also punished beneficiaries of windfalls as well, according to the release.

'Our study provides the first evidence of a non-human primate choosing to punish others simply because they have more,' said Leimgruber, first author of the paper.

'This sort of 'if I can't have it, no one can' response is consistent with psychological spite, a behavior previously believed unique to humans.'

Researchers found Capuchin monkeys will yank on a rope to collapse a table that is holding another's food. Like chimpanzees, Capuchins did collapse tables to punish monkeys that stole food. But they also punished beneficiaries of windfalls as well

'Our findings suggest that the psychological roots of human-like punishment motivations may extend deeper into our evolutionary history than previously thought.' Santos said.

Last month, study suggested macaque monkeys take the welfare of their friends into account when making behavior choices that could reward or punish their peers.

Using an experiment involving pairs of monkeys, juice and airpuffs, scientists have shown macaque monkeys seemingly show empathy - a characteristic thought to be almost uniquely human. Results showing their tendency to reward friends and show prosocial behaviour is shown above

Previous studies have shown that macaques can perceive and seek to alleviate their peers' distress, and scientists have long be trying to work out how altruistic behaviour and empathy has evolved.

Researchers from the Centre of Cognitive Neuroscience in Bron and the University of Lyon, both in France, paired up captive long-tailed and rhesus macaques.

The 14 pairs were made to sit opposite each other and to choose between two visual cues shown on a touchscreen, symbolising a reward or punishment.

Previous studies have shown that macaques (stock image) can perceive and seek to alleviate their peers' distress and scientists have long be trying to work out how altruistic behaviour and empathy has evolved

STUDYING EMPATHY IN MONKEYS

Researchers paired up captive long-tailed and rhesus macaques.

The 14 pairs were made to sit opposite each other and to choose between two visual cues shown on a touchscreen, symbolising a reward or punishment.

The monkeys took turns in making decisions that could impact their own welfare or their partner's, by either granting rewards in the form of a sip of juice, or delivering punishments in the form of a blast of air to the eyes, dubbed an 'airpuff' in the study.

Eye-tracking devices were used to record the monkeys' gaze and eye blinks to look for signs of social engagement and negative effects.

Overall, they observed eight instances of positive or 'prosocial' behaviour when it came to rewarding partners with juice, four indifferent ones and two antisocial ones.

The monkeys took turns in making decisions that could impact their own welfare or their partner's, by either granting rewards in the form of a sip of juice, or delivering punishments in the form of a blast of air to the eyes, dubbed an 'airpuff' in the study.

Eye-tracking devices were used to record the monkeys' gaze and eye blinks to look for signs of social engagement and negative effects.

Researchers Sebastien Ballestaa and Jean-René Duhamel found that the creatures seemed to show empathy to their partner.

'Most monkeys were inclined to refrain from delivering a mildly aversive airpuff and to grant juice rewards to their partner,' they wrote in the study, published in the journal Proceedings of the National Academy of Sciences (PNAS).

Overall, they observed eight instances of positive or 'prosocial' behaviour when it came to rewarding partners with juice, four indifferent ones and two antisocial ones.

'One monkey (M1) displayed consistent prosocial choices with all of its partners, whereas all other animals showed a pattern of prosocial, antisocial, or indifferent choices that depended on partner identity and outcome valence [event].'

The researchers observed eight instances of positive or 'prosocial' behaviour when it came to rewarding partners with juice, four indifferent ones and two antisocial ones. Monkey 'M1' only showed prosocial behaviour, while others showed a mixture (results illustrated above)

Interestingly, a monkey dubbed 'M5' refrained from delivering an airpuff to his female grooming partner, more than to himself, 'suggesting that observing another's discomfort can be more aversive than experiencing it,' the researchers wrote.

They also found that the probability of making a benevolent choice was associated with the amount of mutual gaze between the partners. In particular, they increased the time staring at each other if a treat was awarded.